JPH0412876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method of reading a Tagata code that can represent several bits of information with one code.

[Prior art and its problems]

Conventionally, in this type of Tagata code, the meshes forming the code are arranged in a matrix, so when reading the position information of the meshes, that is, the code, it is not only necessary to align the meshes, but also requires a considerable amount of time. This takes time, which not only prevents the use of the code to its full potential, but also causes the disadvantage of reading incorrect data if the code is tilted with respect to the scanning direction when scanning the code. It was hot.

[Purpose of the invention]

This invention takes into consideration these conventional drawbacks,
The object of this invention is to accurately know the position of the Tagata code, to read the data accurately, and to obtain accurate position information of the Tagata code even if the code is slightly tilted with respect to the scanning direction.

[Summary of the invention]

In order to achieve the object, this invention provides a reference line that is parallel to the Tagata code and has a length equal to the length of one side of the Tagata code, and a first row located on the reference line side of the Tagata code. At least one of the meshes is a dark-colored pixel, and the data is read by scanning the Tagata code along the first direction, and the position of the mesh in the first row of the Tagata code is set to the reference line. Obtain location information as a reference,
Furthermore, the mesh positions in the second and subsequent rows are obtained based on the mesh position information with dark pixels on the reference line side of that row, which makes it easier to obtain tagata code data. The data can be read accurately even if the scanning angle is slightly tilted.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In other words, in Fig. 2, reference numeral 1 indicates the basic configuration of the well-known Tagata cord. For example, four square meshes each having a side of 2 mm are combined in a square shape to form a Tagata cord having a side of 4 mm as a whole. be done. This field code can represent information of a predetermined number of bits by filling out each mesh.
For example, when four meshes are used, in the recognition algorithm of this embodiment, at least one of the meshes in one row on the reference line side is dark-colored, so that 12 types of information can be represented. Now, suppose that when the upper left mesh is filled in, it becomes 0, when the lower left mesh is filled in, it is 1, when the upper right mesh is filled, it is 2, when the lower right mesh is filled, it is 4, and When the upper left and lower left meshes are filled in, it can be set to 8.

In addition, this Tagata code has a first axis line, that is, one line of the cross.In this embodiment, the vertical line is the first line.
The plurality of field cords 1, 1 are arranged at predetermined intervals along the second direction, that is, the direction of the X-axis, which coincides with the direction of It is arranged after.

For example, the length is 4mm and the width is 1mm.
The reference line 3 is the second line from the Tagata code located at the left end.
further to the left by a predetermined interval, for example, 1 mm, and whose longitudinal axis is the first
It is arranged in accordance with the direction of.

Therefore, in the second direction intersecting the reference line 3, one end, that is, the upper end in this embodiment, of the taga cords 1, 1 is connected to one end, that is, the upper end of the reference line 3, and the other The ends, ie, the lower ends, coincide with the other end, ie, the lower end of the reference line 3, respectively.

Further, the reference line 3 is selected to be black in the same way as the color used to fill in the predetermined meshes of the Tagata code 1, but the color is not limited to an achromatic color and can be arbitrarily selected.

Next, a method of reading the tag type codes 1, 1 according to the present invention will be explained.

First, the reading is performed by raster scanning, and the scanning direction is from top to bottom along the first direction in FIG. 1, and the scanning direction is along the reference line in the second direction in FIG. 3 to the Tagata code 1 side, that is, from the left side to the right side. That is, this scanning is called a vertical raster scan from left to right.

Scanning is then started, and formal reading begins only when the reference line 3 has undergone raster scanning. That is, if the raster scan results in a number of consecutive black pixels that are dark colored pixels equal to or greater than a certain value, which corresponds to a little less than 4 mm in this embodiment, then this is extracted as the reference line 3. At the same time, a point 3a at one end of the reference line 3 shown in FIG.
That is, the coordinates of the upper end point and the point 3b at the other end, that is, the lower end point, are determined.

The area of dark pixels that appear next is located next to the reference line 3, and is the left end of the taga code 1a that is scanned first, so scan the line L1 about 0.5 mm ahead from this point L0, that is, the first column. do. At this time, at least one of the two meshes on the scanning line has a dark pixel, so by comparing the upper and lower end points of this pixel on the scanning line, the pixel configuration of the mesh can be determined. It is determined that it is one of A, B, and C in Figure 4.

Furthermore, the pixels in the first column of the adjacent Tagata code 1b, that is, the first column of the code, are the first pixels of the first Tagata code 1a.
When the code in the column is as shown in Figure 4 A, this upper end point
The coordinates of y12 and the lower end point y10 are updated using the code recognition position reference point, that is, the upper end point and the lower end point of the reference line 3 as references. In addition, when the code is as shown in Figure 4 (b), that is, when a dark pixel is on the upper side of the column, the coordinates of the upper end point y12 and lower end point y11 + (lower end point y11 - upper end point y12) of that pixel are set as the code recognition position. Update as a reference point. On the other hand, when the code is as shown in Figure 4 (c), that is, when the dark pixel is at the bottom of the column, the coordinates of the upper end point y11 - (lower end point y10 - upper end point y11) and lower end point y10 of that pixel are coded. Update as the recognized position reference point.

Further, the second row, that is, the mesh on the right side of the field code 1a is recognized by scanning a line L2 2.5 mm to the right from the left end line of that row, as shown in FIG. When the mesh in the first row takes the form shown in Figure 4 A, the y-coordinate of the scanning start point corresponding to the mesh in that row is the upper end point y22 (updated upper end point y22
+ the lower end point after the update y20)/2, or the upper end point after the update if the mesh takes the form of Figure 4 B
y22 and the lower end point y11 before the update, and if the mesh takes the form of Figure 4 C, the upper end point y22 after the update.
Scanning is performed from a position approximately 0.25 mm from the upper end point y11 and the upper end point y11 before updating. The length of each scan is approximately 1.5 mm, and approximately
When a continuous dark color pixel of about 0.8 mm is observed, the mesh is determined to be a dark color, that is, a black mesh. This completes the recognition of the data of the first taga code 1a.

If the second tag type code 1b continues, the position L3 is located 4.5 mm in the scanning line advancing direction from the left end line of the first tag code 1a for which recognition has been completed, that is, the position indicated by the symbol L0 in FIG. Scanning is started at , and the next taga code 1b is recognized.
Therefore, the continuous area of dark color pixels extracted first becomes the leftmost line of the second Tagata code 1b, so
By scanning the line 0.5 mm to the right from here, the mesh in the first row of the second tag type code 1b, that is, the third row counted from the first row of the first tag type code 1a.
A mesh of columns is scanned. Here, it is recognized whether the shape corresponds to A, B, or C in Figure 4 from the upper end point and lower end point updated from the first Tagata code, and the upper end point and lower end point are updated again. Ru. Subsequently, the pixels of the third mesh on the right side of the second Tagata code 1b are extracted. By performing similar operations, subsequent taga codes 1c, 1d...
scan the data.

Next, each data is code-converted and the value of each code is calculated.

Figures 5 and 6 show the permissible range of rotation error, and show a state in which the scanning direction is tilted counterclockwise with respect to the reference line 3 and the Tagata code 1, in other words, the Tagata code 1 is tilted in the scanning direction. Figure 5 shows the relationship between the field code 1 which takes the shape of Figure 7 A, and Figure 6 shows the relationship between the field code 1 which takes the shape of Figure 7 B. .

The limit slope for determining reference line 3 from these figures, that is, the slope of the diagonal line in the figures, is ±13 degrees, and even if data for Tagata code 1 is extracted at this angle, it will not be readable as shown by symbols D and D. It will be understood that all of the scanning lines are located within the mesh to be scanned, allowing errors due to the inclination, and are correctly recognized.

Therefore, it will be understood that in this method, it is possible to recognize the tag-shaped code 1 that allows deviations in the first direction, the second direction, and the rotational direction.

FIG. 7 shows the external appearance of the code reading device 5, in which a pen unit 7 extracts the reference line 3 printed on the object 6, for example, a sheet, and the tag code 1, 1.
and a controller section 8. Pen part 7
is used in close contact with the object 6 and inputs information in the first direction, that is, one-dimensional information; when obtaining two-dimensional information of the Tagata codes 1 and 1, it is used in close contact with that code, that is, the object. In this state, it is moved in the second direction, that is, in the lateral direction.

Furthermore, the pen section 7 and the controller section 8 are
It is configured as shown in the figure. In this figure, the light source 11 is composed of a plurality of light emitting diodes,
When the pen part 7 is in close contact with the Tagata cords 1, 1, they are irradiated. The close-contact line image sensor 12 images one-dimensional information of the tag type codes 1, 1 illuminated by the light source 11. The line sensor driver 13 reads out one-dimensional information based on the output signal from the synchronization generation circuit 14 and outputs it to the signal processing circuit 15. The roller 16 drives the line image sensor 12. Further, the rotation detection circuit 17 detects the rotation angle of the roller 16. Here, from the synchronization generation circuit 14 to the line sensor driver 1
The rotation angle of the roller 16 is detected by the rotation detection circuit 17, and the signal to the controller 8 is generated from the output result and a clock signal from the timing generation circuit 21 in the controller 8. The binarization circuit 18 binarizes the one-dimensional signal that has been subjected to processing such as amplification and filtering by the signal processing circuit 15, and its threshold value is based on the average density value or maximum intensity value of one cycle before. It is possible to automatically set it by the ratio etc. In the controller section 8, the line memory 23 receives the binarized image signal in response to a clock signal. The dedicated code reader 24 processes the contents of the one-dimensional information in the line memory 23 using the timing generation circuit 21, and obtains the mesh information of each tag type code 1. The code conversion circuit 25 converts the mesh information of the Tagata code 1 into a code value. The serial converter 26 converts the code value into serial data, and the RS232C port 27 outputs the serially converted data to the outside. Note that 28 is a power source.

Furthermore, FIG. 9 shows the dedicated code reader 24 and code conversion circuit 25 more specifically.
31 is a line detection circuit, 32 is a line end point detection circuit, 33 is an upper end point memory, 34 is a lower end point memory, 35 is a code left side discrimination circuit, 36 is a right upper scanning starting point, 37 is a right lower scanning starting point, 38 39 is a mesh analysis circuit, 41 is a code determination circuit, and 42 is a table.

Next, the operation in the above configuration will be explained.

First, the pen part 7 is brought into close contact with the tag code 1 printed on the object 6. Then, the field code 1 is illuminated by the light source 11 and further imaged by the contact type line image sensor 12. In addition, the line detection circuit 31 of the dedicated code reader 24 checks whether or not the number of black pixels in the data previously read into the line memory 23 is equal to or greater than a certain value, that is, in this embodiment, the number of pixels is a little less than 4 mm. For this purpose, the rotation of the roller 16 is detected by the rotation detection circuit 17 until the first line, that is, the reference line 3 is detected, and the one-dimensional information captured in the contact type line image sensor 12 is continuously transmitted to the signal processing circuit 15, The signal is input to the line memory 23 through the binarization circuit 18.

When the line detection circuit 31 detects the reference line 3, the line end point detection circuit 32 records the coordinates of its upper end point and lower end point in the upper end point memory 33 and lower end point memory 34, respectively. Information on the reference line 3 can thus be obtained.

Next, the rotation of the roller 16 is detected by the rotation detection circuit 17, and a special test is performed to determine whether or not black pixels continue by a certain value or more in the data read into the line memory 23 again from a point after an offset of, for example, a little over 1 mm. The line detection circuit 31 in the code reader 24 checks the line, and the rotation detection circuit 17 detects the rotation of the roller 16 until the next line is detected, and the one-dimensional information captured in the contact line image sensor 12 is continuously transmitted. The signal is then input to the line memory 23 through the signal processing circuit 15 and the binarization circuit 18.

If the line detection circuit 31 detects a line, it is the left end of the tag code 1, so the rotation of the roller 16 is detected by the rotation detection circuit 17, and the offset of 1.5 mm and one-dimensional information of the point are sent to the contact type line image sensor. 12, the signal is input to the line memory 23 through the signal processing circuit 15.

Next, the information inputted to the line memory 23 is determined by the code left side discriminating circuit 35 to determine whether it is a tag type code shown in FIG. 4A, B, or C.

In other words, as the determination point of the mesh code in the first column of the field code 1, in the case of Figure 4 A, the coordinates of the upper end point and the lower end point are used, and in the case of Figure 4 B, the upper end point and the lower end point + (lower end point) The coordinates of the point minus the upper end point) or, in the case of FIG. In addition, the coordinates of the scanning start point for recognition of the second row, that is, the mesh on the right side, are the upper end point (upper end point + lower end point) / 2 in the case of the tag type code shown in Fig. 4 A, In the case of (b), scan the upper end point and the lower end point before the update, and in the case of Fig. 4 (c), scan the upper end point on the right side at a position 0.25 mm from the upper end point after the update and the upper end point before the update. The starting point 36 and the lower right scan starting point 37 are recorded.

The rotation of the roller 16 and the one-dimensional information at the point 2.5 mm from the left end of the tag code 1, which has already been obtained by the rotation detection circuit 17, are transferred to the line through the contact type line image sensor 12, the signal processing circuit 15, and the binarization circuit 18. input into memory 23;

For this input data, the code right side discrimination circuit 38 selects the already determined right upper scanning start point 36,
The mesh information is obtained using the lower right scanning start point 37.
Then, the mesh analysis circuit 39 receives this information and outputs the mesh value.

Next, the data acquisition position is set to the left end of the field code already obtained, or to a point 4.5 mm offset by the rotation of the roller 16 and the rotation detection circuit 17.

Information on all the meshes can be obtained by repeating the extraction operation of the taga code in the same manner.

The mesh information obtained in this manner is sequentially input to a code conversion circuit 41, code converted using a table 42, and output as a code value.

〔Effect of the invention〕

As mentioned above, this invention runs parallel to the Tagata cord.
Moreover, since a reference line having a length equal to the length of one side of this Tagata code is provided, it is extremely easy to extract the code, and therefore the burden on the user can be extremely reduced. Tagata code can be recognized accurately.

In addition, at least one mesh in the first column located on the reference line side of the taga code is a dark-colored pixel, and the data is read by scanning the taga code along the first direction. 1
The position of the mesh in the column is obtained based on the position information of the reference line, and the position of the mesh in the first column of the second and subsequent Tagata codes is obtained from the dark-colored mesh on the reference line side of the Tagata code located before it. Since the mesh position information obtained by applying pixels is obtained as a reference, even if the relative angle between the direction of movement of the scanning line and the reference line and the arrangement direction of the tag form code in the second direction changes slightly, the error can be sufficiently tolerated. , Therefore, it is possible to recognize a tag code that can tolerate deviations in the first direction, the second direction, and the rotational direction.

[Brief explanation of drawings]

Fig. 1 shows an embodiment of the method for reading the taga code according to the present invention, and shows the layout of its patterns, Fig. 2 is a configuration diagram of the taga code, Fig. 3 is an explanatory diagram showing the reading position, and Fig. 4 is a diagram showing the configuration of the taga code. The figure shows the pattern showing the type of tag code, Figures 5 and 6 are explanatory diagrams showing the relationship between the scanning line advancing direction and the tag code, Figure 7 is a perspective view of the reading device, and Figure 8 shows the pen section and FIG. 9 is a block diagram of the controller section, and FIG. 9 is a block diagram of the dedicated code reader and code conversion circuit. 1...Tagata code, 3...Reference line, 5...Code reading device, 6...Object, 7...Pen part, 8
... Controller section, 11 ... Light source, 12 ... Contact type line image sensor, 13 ... Line sensor driver, 14 ... Synchronization generation circuit, 15 ... Signal processing circuit 16 ... Roller, 17 ... Rotation detection circuit , 18... Binarization circuit, 21... Timing generation circuit, 23... Line memory, 24... Dedicated code reader, 25... Code conversion circuit, 26...
...Serial converter, 27...RS232C port, 3
1...Line detection circuit, 32...Line end point detection circuit, 33...Upper end point memory, 34...Lower end point memory, 35...Code left side discrimination circuit, 36...Right upper scanning start point, 37...Right side Lower scanning start point, 3
8...Code right side discrimination circuit, 39...Mesh analysis circuit, 41...Code determination circuit, 42...Table.

Claims (1)

[Claims] 1 The axial center line of the Tagata code, which combines four square meshes in a Tagata shape and displays the code by the shade of the color of each mesh, is aligned with the first direction, and the axis of this Tagata code is A reference line parallel to the line and having a dimension equal to the dimension of one side of the tag type code is provided at a predetermined interval from the tag type code, and further located on the reference line side of the tag type code in the first direction. At least one of the meshes in the first row is a dark-colored pixel, and one end of the Tagata code is aligned with one end of the reference line in a second direction intersecting the reference line. , further aligning the other end of the Tagata code with the other end of the reference line, scanning the Tagata code and the reference line from one end of each toward the other end; By advancing the scanning line in this scan from the reference line toward the Tagata code side along the second direction, the data of the Tagata code is read, and the data of the Tagata code is read first in the advancing direction of the scanning line. The position of the mesh in the first row in the first direction of the Tagata code on the side of the reference line is
The positions of the meshes in the second and subsequent rows are obtained by using the position information in the direction of A method of reading a Tagata code in which position information of the other end is obtained as a reference.